Removal of mercury from waste materials

ABSTRACT

Mercury is efficiently and effectively removed from waste materials by a process and apparatus which heats waste containing mercury to temperatures well above the boiling point of mercury to create a vapor stream laden with mercury vapor. This vapor stream is first cooled to a temperature at least 100° F. above the boiling point of mercury, which allows some condensation of impure mercury with other materials, and creates a second vapor stream comprising mercury. This second vapor stream is then cooled to a temperature below the boiling point of mercury to condense more pure condensates of mercury. A third cooling step optionally may then be used to cool the remaining vapor stream to temperatures below the boiling point of mercury to remove further mercury content from the vapor stream. Filters and/or scrubbers may be added to remove trace amounts of mercury from the effluent vapor stream.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to processes and apparatus for the removalof mercury contaminants from waste materials. In particular, the presentinvention describes a thermal recovery process (which allows ambient airto be present within the system) and apparatus for the efficient removalof mercury and the recovery of mercury from waste materials, especiallywaste materials such as batteries, crushed lamps, switches and the like.

2. Background of the Art

One of the many serious forms of pollution which has been created byindustry has been the levels of mercury introduced into the environmentfrom manufactured goods. Amongst the more prominent incidents involvingmercury were the Minnimata contamination in Japan and the swordfishwarnings in the 1950's. At Minnimata, mercury waste from a localmanufacturing company contaminated a bay and many local residentsingested high levels of mercury from fish. The effects of mercury, likethose of many heavy metals, are quite devastating, prolonged, anddifficult to treat. Mercury is particularly dangerous because, eventhough it is a liquid and its boiling point is about 675° F. (356.6°C.), it is hygroscopic or hydroscopic and enters the surrounding air andwater system quickly. It is also injurious in small doses which can berapidly ingested from breathing contaminated air and is highlypersistent after it has been ingested.

Even with its serious potential for harm, mercury has many significantcommercial uses and is widely accepted in the electrical and electronicsarea as a conductor. Mercury is conventionally used, for example, as acomponent in batteries, as a contact for electrical switches, as circuitconnectors and switches in thermostats, and as conductors in fluorescentlamps. Because of the large volume of use for mercury, there is also alarge volume of mercury waste which is created each year. Mercury maynot be deposited in solid waste landfills because of its known hazardouseffects on the environment, and burying it is merely a temporary andunsafe disposal method since mercury will readily enter the water tableand spread in the environment. It can be further distributed within theecosystem if ingested by bacteria, insects or the like.

One method of recovering mercury commercially is to take the wasteproducts containing mercury, place them within a drum or container(e.g., a fifty-five gallon drum), place the container within anautoclave, and heat the container well above the boiling point ofmercury to evaporate the mercury into a collection point (e.g.,condensation chamber).

Earlier, non-public attempts by the present inventors at such mercurycollection systems used long, repeating cooling pipes (much like steamradiators) to air cool the mercury in the heated waste stream from theautoclave. Solidified (liquefied) mercury would be drained from the pipe(with other condensed materials) and the residue of the waste streamwould then be cooled to further condense materials (including additionalmercury) in the waste stream. This process would have been highlyinefficient, and would have been quite costly to run. The long length ofcooling pipes needed for the process would clog from deposited mercury(usually in the form of amalgams or cocondensed waste) within the pipes,the lining of the pipes could easily react with the mercury, causingremoval and/or deposition of metal or amalgam, extreme amounts of heatwould be produced locally around the pipes which would require coolingmeasures for the work environment, and other adverse features of thisattempted arrangement dictated against this type of process. The volumecapability of systems which work only with batch processing of wastecontaining mercury also greatly limit the ability of such systems toaddress the volume requirements of mercury waste treatment needs.

To respond to the need for more efficient and improved quality recoveryand removal of mercury from water streams, improved processes andequipment are needed.

SUMMARY OF THE INVENTION

The present invention relates to a process and apparatus for the removalof mercury from waste materials and for the recovery of mercury in anenvironmentally safe and economic manner. The method is performed byapparatus which heats the mercury waste (in a batch or continuousfashion) and which recovers mercury from the effluent vapor stream fromthe heating step by repeated, controlled cooling of the vapor stream toselectively condense materials from the vapor stream. The heated vaporstream is first cooled from the high temperatures directly emitted froma heating zone (at temperatures above 1000° F. [538° C.]) down to atemperature above the boiling point of mercury (˜675° F. [˜357° C.]) toremove additional pollutants from the stream other than the majorportion of the mercury. This is followed by subsequent cooling of thevapor stream to a temperature below the boiling point of mercury, andthen preferably transferred to a third cooling zone which furthercondenses the majority of condensable residues in the heated vaporstream. The gaseous stream may then be further filtered to reduce theamount of other hazardous pollutants in the vapor (gas) stream. This ispreferably done by a system of scrubbers and filters. By this processand the described apparatus, very high percentages of the mercury in thewaste can be recovered with little or no introduction of mercury intothe waste stream or the environment.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a diagrammatic representation of the waste vapor streamgenerating apparatus 2 used in the practice of the present invention.

FIG. 2 shows a diagrammatic view of the cooling 70 and filtering 80portions of the apparatus of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The toxicity and persistence of mercury wastes are well documented andproven in scientific literature. The difficulty in its recovery is inlarge part due to the precise properties which make mercury such aserious environmental threat. Although it has a lower vapor pressurethan most heavy metals, it combines readily with other materials to becarried away in various forms (as a gas, liquid or solid), is morereadily absorbed and carried by the atmosphere and water, and it canbecome active towards organic systems either in its original elementalform or in a readily converted form. The difficulty in designing asystem for mercury recovery which will not create significantenvironmental problems, yet will work efficiently and economically, hasbeen a serious challenge. The present apparatus and process improvesupon the existing technology used for recovery of mercury and itselimination from waste streams.

FIG. 1 shows a diagrammatic representation of the waste vapor streamgenerating apparatus 2 used in the practice of the present invention.Waste material containing mercury (not shown) is deposited into aninitial collection hopper 4, preferably through a vacuum line 6 throughwhich pressure is maintained to force waste material through the vacuumline 6 into the collection hopper 4. The vacuum should be sufficientlystrong (e.g., a draw which is greater than 1 lb/in², preferably at least5 lb/in², more preferably at least 7 or 9 lb/in², and most probably nomore than 10 lb/in²) to assure that mercury vapor, which surrounds themercury containing waste, does not escape from the vacuum line 6 and theambient area around the hopper 4. The waste containing material shouldbe of dimensions that can readily enter the vacuum line 6 withoutreadily blocking or damaging it. The opening to the vacuum line 6 may beof any useful dimension, but it has been found that diameters of fromabout 2 to 12 inches (5 to 31 cm) are particularly desirable, withdimensions of 3 to 8 inches (7.6 to 21 cm) preferred and 5 to 7 inches(13 to 17.7 cm) most preferred.

The inner surface 8 of the hopper 4 is preferably coated (e.g., teflon,polysiloxanes, abrasion resistant polymers, etc.) to reduce the effectsof the significant abrasion which can occur from passage of wastematerial through the hopper 6 to the exit 10 at the bottom. As the wastematerial will often include metal scrap, glass, inorganic oxide powderand the like, there is significant abrasive action against the interiorsurface 8. A flow control means or mechanism 12 should be present at theexit 10 from the hopper 4 to promote and control the flow of wastematerial. Such mechanisms include rotary airlocks, pinch valves, andslide gate valves to keep negative pressure on the system. Rotaryairlocks are preferred because of their durability and efficiency. A cap11 may be placed over the rotary airlock 12 to reduce damage to orjamming of the rotary airlock 12. The diameter of the exit 10 shouldalso be sufficiently large to allow waste to pass through the system.Dimensions of at least about 4 to 16 inches (10 to 42 cm) are preferred.A carrying tube 14 extends downward from the exit 10 towards the oven22. The tube 14 will usually have an angled portion 16 which enters theoven 22 through a port 18 in a side 20 of the oven 22. The angle 24 ofthe angled portion 18 of the carrying tube 14 should not exceed 50° andpreferably should be less than or equal to 45° from vertical. It is morepreferable that it be less than 40° to prevent backup or stoppage ofwaste material within the carrying tube 14.

After the angled portion of the tube 16 enters the oven 22 through theport 18 in the side 18 of the oven 20, waste material (not shown) isdeposited onto a carrying means 26 within the oven 22. The carryingmeans 26 shown is like the drive in a screw auger, with continuousblades 28 on a shaft 30. The preferred carrying means is a rotary kilnin which the flights are secured to the interior walls of the kiln toform a rotating path. Waste material (not shown in this figure) isdeposited from the port 18 onto the carrying means 26 and carriedthrough the oven 22. The temperature within the oven 22 is maintained ata high enough level to assure evaporation of the mercury from the wastematerial. That temperature must be above 900° F., preferably above 1000°F., more preferably above 1100° F., and most preferably at 1200° F. orabove. The oven 22 is shown tilted at an angle 32 to provide anotherspecific benefit to the configuration, especially where the screw drive26 is shown as the carrying means 26. With an angle 32 between 2.5° and15°, waste material which is moved by the blades 28 of the screwcarrying means 26 is also tumbled within the oven 22 to increase theamount of time in which surface area of the waste material is exposed.This tumbling increases the efficiency of the evaporation from thesurface of the waste. This is a significant advantage, and iseffectively accomplished only with appropriate angling of the oven 22with respect to the angle (not specifically shown) formed between theblades 28 and the shaft 30 of the screw carrying means 26. If the pitchof the blades changes, the angle 32 of the oven may also change withinacceptable limits, even beyond the 2.5° and 15° previously mentioned.The heating zone (e.g., an oven or kiln) may be alternatively viewed asa means for moving said material within said heating zone, the materialbeing moved by means of blades on a shaft and said shaft within saidheating zone, with the movement within said heating being at an anglebetween 2.5° and 15 to the ground (outside of the heating zone, sincethe angle of the movement is relative to the effects of gravity pullingmaterial downward). That angle 32, or the other angle for blades 28 of adifferent pitch is based upon the minimum angle assuring tumbling andexposure of the waste material and the maximum angle preventing thewaste from tumbling back over a trailing edge of the blades 28 on thecarrying means 26. Vibrating carriers, drag chain carriers and the likecould also be used, but they have structural and functional limitationssuch that the screw drive 26 is highly preferred. It is particularlydesirable, as shown later, to have waste material enter the side 20 ofthe oven 22 through the port 22 and be deposited on a blade of thecarrying means 26 beyond the first turn of the blade away from the port18. This prevents waste material from being dumped onto a floor surfaceof the oven 22.

The passage of waste material through the heating area of the oven 22removes the vast majority of entrapped mercury in the waste and carriesit as a vapor stream (not shown) through an exit port 34 to vaporcarrying pipes (or tubing) 36 to a velocity drop box 38 to help removesolid materials (not shown) such as dust and other particulates from theheated vapor stream (not shown). The velocity drop box 38 preferablycontains at least one and more preferably two heating means 40 tomaintain the temperature of the vapor stream within the velocity dropbox 38 and through the velocity drop box 38 exit port 42. Without theseheating elements 40, it was found that the mercury would have a greatertendency to condense or amalgamate within the drop box 38, even thoughthe temperature was still well above the boiling point of mercury. Thiswas because of the strong affinity of the mercury for other materialswithin the system (within the vapor stream). The temperature of thevapor stream to the velocity drop box 38, in the velocity drop box, andexiting the velocity drop box should remain at least within 100° C. ofthe temperature within the exit stream of vapor from the oven 22 in thecarrying tube 36 (preferably greater than 900° F., more preferablygreater than 1000° F., still more preferably greater than 1100° F., andmost preferably 1200° F. or more. It is preferable that the temperatureat any point along this path (from oven exit port 34 to carrying tube 36to velocity drop box 38 through the exit 42) should remain within 50° C.of the oven temperature, more preferably within 25° C. of the oventemperature, and even equal to the oven temperature. That oventemperature must be above 900° F, preferably above 1000° F., morepreferably above 1100° F., and most preferably at 1200° F. or above.

Solid material (not shown) collected in the velocity waste box 38 may beremoved through waste outlet 43 in the velocity drop box 38. This wouldbe done on a batch basis. If any significant mercury content is found inthis waste, it can be recycled through the oven by redepositing it intothe hopper 6.

Solid waste material (not shown) which passes through the oven 22 mayexit through a solid exit port 46 and pass into a solid waste tubing 48and taken to a solid waste hopper 50.

FIG. 4 shows the cooling section 70 of the present apparatus. The hotvapor from the oven 22 after the velocity drop box 38 passes from ventintubing 42 to the first cooling unit 60. This cooling unit 60 comprisesan inlet tube 62 which carries the heated vapor (not shown) in thepassageway 64 within the tubing 62. The temperature of the vapor beforeit enters the tubing 62 is at or about the exit temperatures mentionedas desirable for the vapor vented from the velocity drop box 38. Thattemperature must be above 900° F., preferably above 1000° F., morepreferably above 1100° F., and most preferably at 1200° F. or above. Thevolume of vapor entering the first cooling unit 60 is preferably above50 cubic feet per minute (cfm), more preferably above 100 cfm, stillmore preferably above 125 cfm, and in the actual operation of theequipment is about 150 cfm. at the elevated temperatures within thetubing 62. The flow is preferably at a maximum of 200 cfm, morepreferably below 175 cfm. The heated vapor passes down the tubing 62 tothe opening 66 at the bottom of the tubing 62. The first cooling unitshould have an insulation 68 around the exterior or interior walls tomaintain confinement of the heat captured from the vapor stream. Theremust be a cooling capability within the tank as with a cooling means 69which may be a water flow cooled surface (e.g., with an aqueous systemof water plus polyethylene glycol at 20 degrees F.). Other coolingsystems, e.g., air flow cooled, Peltier units, etc.) may be used, butnon-contact water cooling systems are preferred. When the heated vaporstream (not shown) is cooled in the cooling unit 60, material condenses,drops within the collection area 72 and is collected within a chamber 74where the first traces of mercury and other condensates appear asproduct 76. This first cooling unit preferably cools the vapor stream toa temperature which is above the boiling point of mercury (˜675° F.[˜357° C.]). The temperature is preferably above 700° F. to assure thatmost of the mercury remains in the vapor phase. Even though the firstcooling unit 60 does not cool the gaseous stream to a temperature belowthat boiling point temperature, some mercury is pulled out of the vaporphase by its attraction to other condensates, such as decomposedpolymer, waxes, resins, and other materials from within the waste streamwhich were evaporated during the oven heating step. The condensate atthis point is not commercially useful, but should actually be added backto the initial waste stream before treatment by the oven byreintroduction to the hopper 6.

The vapor stream, now at a first reduced temperature, has passed fromthe exit 66 of the tubing 62, passed into the major cooling area 69,passed through openings 82 at the top of the interior of the coolingunit 62, and exited through a port 84 into a tubing 90 which leads to asecond cooling unit 91. This unit may be substantially identical inconstruction to the first unit, with vertical tubing 92, pipe interior94, exit 96, collection area 102, chamber 104, product 106 (which is nowrelatively pure mercury, e.g., >90% by weight mercury, even as muchas >95% by weight mercury), insulation 98, cooling surface 99, exit port108, and exit tubing 110. This exit tubing is preferably, but notessentially connected to a third cooling unit 111. The third coolingunit 111 is needed depending upon the final second reduced temperatureachieved in the second cooling unit 91. The temperature of the vaporstream leaving the second cooling unit 61 should be substantially belowthe boiling point of mercury. It is preferred that this temperature bebelow 450° F., more preferably below 375° F., and most preferably below325° F. or equal to or less than 300° F. If there is the preferred thirdcooling unit 111, the construction of the preferred third cooling unit111 preferably is again similar to the construction of the first coolingunit 60, except for the following features. The flow is preferablydownward only, and through a multiple number of tubes. Additionally theexit ports are at the bottom, because different materials are vented andcollected in the third unit 60. After passing through a vertical pipe112, the vapor stream, now at a lower but still elevated temperature,passes through the vertical opening 114, and through the exit 116. Acollection chamber 122 is at the bottom of the unit, but an overflowtube 126 is present to carry away lower density materials. Some mercury124 is still collected in the chamber 122. Lighter weight materialscarried away by an overflow tube 126 would include water (not shown)which is collected in a chamber 128. A vapor vent 126 is also present atthe bottom of the chamber to carry the vapor flow out of the coolingunit 111. The vapor flow is directed through tubing 121 to a firstfilter unit 130, then through additional tubing 123 to a second vaporfilter unit 140, and by further tubing 125 to an air scrubber 142. Vaporvented through a vent 144 would contain substantially no mercury andwould be environmentally safe.

The process of the present invention may be described as follows, withor without reference to the flow diagram of FIG. 2. Step 1—Mercurycontaining waste is heated to a temperature at least 300° F. (166.7° C.)above the boiling temperature of mercury. Preferably the waste is heatedto a temperature at least 400° F. (222.2° C.), and more preferably atleast 500° F. (277.8° C.) above the boiling point of mercury. The systemof the invention in experimental operation provides an internal oventemperature of about 1200° F. A vapor stream is removed from the ovenand transported at elevated temperatures (approximately equal to or atleast within 100-200° F. of the oven temperature) to a first coolingunit (with or without intermediate steps, such as the velocity drop boxand heating elements) where the temperature of the vapor stream isreduced by at least 200° F. to a temperature which is still above theboiling point of mercury. Preferably the temperature drop in the firstcooling unit is at least 300° F., more preferably at least 350° F. to450° F. The actual temperature drop in the performing apparatus is 500°F., to a temperature of 700° F. from an entering temperature of 1200° F.Condensate is removed from the vapor stream, and the stream is then sentat the first elevated exit temperature of the first cooling unit to asecond cooling unit. The second cooling step reduces the temperature ofthe vapor stream to a second reduce vapor exit temperature by at least200° F., preferably at least 250 to 300° F., and in actual operation wasoptimized at about a 400° F. temperature drop to about 300° F. Mercurycondensate at a fairly pure level (e.g., >90% by weight) is collectedand the vapor stream, at the second reduced, but still elevated exittemperature to a preferred third cooling unit. The third cooling unitreduces the temperature of the vapor stream to less than the boilingpoint of water, preferably less than 100° F., more preferably less than75° F., and most preferably below 50° F. The actual preferredtemperature during operation is about 40° F. to reduce the vaporpressure of mercury to 2.228×10⁻⁴ mm/Hg or less. Further condensate,including some hazardous materials is collected, and the vapor stream isthen treated for removal of undesirable wastes. This further removal isby filtration, as by activated (especially Sulfur activated) carbonfilters, with preferably two series filtrations performed, which is inturned followed by air scrubbers (e.g., water air scrubbers). These lastfilters are safety backups to insure that less pollutant may escape thesystem.

The volume flow of vapor leaving the heating zone and/or entering thefirst cooling element has been estimated above as about 150 cfm (cubicfeet per minute). This amount is based upon the actual size of theequipment used and the gas pressure maintained across the system. Withlarger equipment, the volumes could always be greater, and converselysmaller with smaller equipment. This volume of gas flow through thesystem is not uniform in volume. As the air is cooled, the volume of thegas stream (and the rate of flow) diminishes, primarily because of thereduction in temperature and not because of mass removal from the gasstream. In the first cooling system, for example, the gas flow may bereduced by at least 10% by volume (more preferably at least 15% byvolume) primarily because of the temperature drop (e.g., 1200° F. to700° F., which is a drop of about 500° F./1750 absolute degrees, or28%). In the second cooling element, the temperature drop may be about400° F. compared to about 1250 degrees absolute or about 30%. The dropin volume would be approximately proportional to the percentagetemperature drop. In the third cooling element, the percentage volumedrop may be as little as 260/850 or about 30%. The volume flow rate ofthe vapor stream therefore may drop by at least 40% or even more than60% when passing from the heating zone until the vapor stream exits thethird cooling unit, passing from as much as 1200° F. to less than 60° F.and even to 40° F.

What we claim is:
 1. A process for the removal of mercury from materialsand for the recovery of mercury comprising: heating material whichcontains mercury to a temperature of at least 900° F. in a heating zoneto create a first gaseous phase which contains mercury, directing saidfirst gaseous phase at a temperature of at least 900° F. to a firstcooling unit which reduces the temperature of said gaseous phase by atleast 100° F. to a temperature which is above the boiling point ofmercury, collecting a first condensate which is condensed from saidgaseous phase which enters into said first cooling unit and sending asecond gaseous phase which contains mercury and which second gaseousphase is at a temperature above the boiling point of mercury to a secondcooling unit, and in said second cooling unit, reducing the temperatureof said second gaseous phase to a temperature at least 100° F. below theboiling point of mercury, collecting a condensate which comprisesmercury, and sending a third gaseous phase out of said second coolingunit at a temperature which is at least 100° F. below the boiling pointof mercury.
 2. A process for the removal of mercury from materials andfor the recovery of mercury comprising: heating material which containsmercury at a temperature of at least 1000° F. to create a gaseous phasewhich contains mercury, directing said gaseous phase at a temperature ofat least 1000° F. to a first cooling unit which reduces the temperatureof said gaseous phase by at least 200° F. to a temperature which isabove the boiling point of mercury, collecting a first condensate whichis condensed from said gaseous phase which enters into said firstcooling unit and sending a second gaseous phase which contains mercuryand which second gaseous phase is at a temperature above the boilingpoint of mercury to a second cooling unit, in said second cooling unitreducing the temperature of said second gaseous phase to a temperatureat least 100° F. below the boiling point of mercury, collecting acondensate which comprises mercury, and sending a third gaseous phaseout of said second cooling unit to a third cooling unit at a temperaturewhich is above 200° F., but is at least 100° F. below the boiling pointof mercury, and sending said third gaseous phase to a third cooling unitwhich cools said third gaseous phase by at least 100° F. to atemperature which is below the boiling point of water, therebycondensing both additional mercury and water within said third gaseousphase and emitting a fourth gaseous phase.
 3. The process of claim 1wherein after sending a third gaseous phase out of said second coolingunit at a temperature which is above 100° F., but at least 100° F. belowthe boiling point of mercury, passing said third gaseous phase throughat least one filter which is capable of withdrawing mercury from saidthird gaseous phase.
 4. The process of claim 1 wherein after said firstgaseous phase is heated to at least 900° F. and before it enters saidfirst cooling unit, said first gaseous phase passes through a velocitydrop box.
 5. The process of claim 4 wherein said first gaseous phase isheated within said velocity drop box.
 6. The process of claim 5 whereinthe temperature of said first gaseous phase entering said velocity dropbox is within 50° F. of the temperature of said first gaseous phase whenit exits said velocity drop box.
 7. The process of claim 2 wherein aftersaid first gaseous phase is heated to at least 1000° F. and before itenters said first cooling unit, said first gaseous phase passes througha velocity drop box.
 8. The process of claim 7 wherein said firstgaseous phase is heated within said velocity drop box.
 9. The process ofclaim 8 wherein the temperature of said first gaseous phase enteringsaid velocity drop box is within 50° F. of the temperature of said firstgaseous phase when it exits said velocity drop box.
 10. The process ofclaim 1 wherein said first gaseous phase is at a temperature of at least1100° F. within said heating zone.
 11. The process of claim 10 whereinsaid first gaseous phase is cooled within said first cooling unit to atemperature between 700° F. and 800° F.
 12. The process of claim 10wherein said second gaseous phase is cooled in said second cooling unitto a temperature between 250° F. and 400° F.
 13. The process of claim 1wherein said material which contain mercury is tumbled while it is beingtransported within said heating zone.
 14. The process of claim 2 whereinsaid material which contain mercury is tumbled while it is beingtransported within said heating zone.
 15. The process of claim 12wherein said fourth gaseous phase is passed through at least twoconsecutive filters which remove mercury from said fourth gaseous phase.16. The process of claim 15 wherein a water scrubber is used to cleangaseous material after it has passed through said two consecutivefilters.
 17. Apparatus for the removal of mercury from materials and forthe recovery of mercury comprising: a confined heating area having aheating zone, which heating area can heat material inside said heatingzone at a temperature of least 900° F. to create a first gaseous phasewhich contains mercury, a fluid conductive path for directing said firstgaseous phase at a temperature of at least 900° F. to a first coolingunit which reduces the temperature of said gaseous phase to atemperature above the boiling point of mercury, collection means forcollecting a first condensate which is condensed from said gaseous phasewhich enters into said first cooling unit and a fluid conductive pathfor directing a second gaseous phase which contains mercury out of saidfirst cooling unit and which second gaseous phase is at a temperatureabove the boiling point of mercury to a second cooling unit, a secondcooling unit which reduces the temperature of said second gaseous phaseto a temperature below the boiling point of mercury, and a collectionmeans for collecting a condensate which comprises mercury, and a fluidconductive path sending a third gaseous phase out of said second coolingunit at a temperature which is above 100° F., but at least 100° F. belowthe boiling point of mercury, and after said second cooling unit, afluid conductive path directing said third gaseous phase through atleast one filter which is capable of withdrawing mercury from said thirdgaseous phase.
 18. Apparatus for the removal of mercury from materialsand for the recovery of mercury comprising: a confined heating areahaving a heating zone, which heating area can heat material inside saidheating zone at a temperature of least 900° F. to create a first gaseousphase which contains mercury, a fluid conductive path for directing saidfirst gaseous phase at a temperature of at least 900° F. to a firstcooling unit which reduces the temperature of said gaseous phase to atemperature above the boiling point of mercury, collection means forcollecting a first condensate which is condensed from said gaseous phasewhich enters into said first cooling unit and a fluid conductive pathfor directing a second gaseous phase which contains mercury out of saidfirst cooling unit and which second gaseous phase is at a temperatureabove the boiling point of mercury to a second cooling unit, a secondcooling unit which reduces the temperature of said second gaseous phaseto a temperature below the boiling point of mercury, and a collectionmeans for collecting a condensate which comprises mercury, and a fluidconductive path sending a third gaseous phase out of said second coolingunit at a temperature which is above 100° F., but at least 100° F. belowthe boiling point of mercury, and a fluid conductive path directing saidthird gaseous phase to a third cooling unit which cools said thirdgaseous phase by at least 100° F. to a temperature which is below theboiling point of water, emitting a fourth gaseous phase.
 19. Theapparatus of claim 18 wherein there is a fluid conductive path directingsaid fourth gaseous phase is out of said third cooling unit and passingsaid fourth gaseous phase through at least one filter which is capableof withdrawing mercury from said fourth gaseous phase.
 20. A process forthe removal of mercury from materials and for the recovery of mercurycomprising: heating material which contains mercury to a temperature ofat least 900° F. in a heating zone to create a first gaseous phase whichcontains mercury, directing said first gaseous phase at a temperature ofat least 900° F. to a first cooling unit which reduces the temperatureof said gaseous phase by at least 100° F. to a temperature which isabove the boiling point of mercury, collecting a first condensate whichis condensed from said gaseous phase which enters into said firstcooling unit and sending a second gaseous phase which contains mercuryand which second gaseous phase is at a temperature above the boilingpoint of mercury to a second cooling unit, and in said second coolingunit, reducing the temperature of said second gaseous phase to atemperature at least 100° F. below the boiling point of mercury,collecting a condensate which comprises mercury, and sending a thirdgaseous phase out of said second cooling unit at a temperature which isabove 100° F., but at least 100° F. below the boiling point of mercury.21. The process of claim 2 after said fourth gaseous phase is out of acooling area within said third cooling unit, passing said fourth gaseousphase through at least one filter which is capable of withdrawingmercury from said fourth gaseous phase.
 22. The apparatus of claim 18wherein said material within said heating zone is moved by means ofblades on a shaft and said shaft within said heating zone is at an anglebetween 2.5° and 15 to the ground.
 23. The apparatus of claim 19 whereinsaid material within said heating zone is moved by means of blades on ashaft and said shaft within said heating zone is at an angle between2.5° and 15 to the ground.
 24. The apparatus of claim 22 wherein meansare available for introducing said material into said heating zone andsaid means for introducing said material deposit said material past afirst complete turn of said blades on said shaft.
 25. The apparatus ofclaim 23 wherein means are present for introducing said material intosaid heating zone and said means for introducing said material depositsaid material past a first complete turn of said blades on said shaft.26. The apparatus of claim 20 wherein after said first gaseous phasewhich contains mercury leaves said heating zone, but before said firstcooling unit, there is a velocity drop box.
 27. The apparatus of claim26 wherein said material within said heating zone is moved by means ofblades on a shaft and said shaft within said heating zone is at an anglebetween 2.5° and 15 to the ground, and wherein means are present forintroducing said material into said heating zone and said means forintroducing said material deposit said material past a first completeturn of said blades on said shaft.
 28. The process of claim 13 whereinsaid tumbling is performed by blades on a shaft which blades tumble saidmaterial which contains mercury.
 29. The process of claim 28 whereinsaid blades move the material which contains mercury at an angle withrespect to ground outside of the heating zone, and said angle is between2.5° and 15° with respect to said ground.
 30. The process of claim 29wherein said first gaseous phase passes through a velocity drop box andsaid first gaseous phase is heated within said drop box.